Grinding wheel dressers



June 19, 1962 R. s. M CONNELL GRINDING WHEEL DRESSERS Filed May 25, 1960 IN V EN TOR.

ROBERT S. MGCONNELL M r/4Z3;

ATTORNEYS United States Patent 3,039,451 GRINDING WHEEL DRESSERS Robert S. McConnell, Urbana, Ohio, assignor to The Desmond-Stephan Mfg. Co., Urbana, Ohio, 21 corporation of Ohio Filed May 23, 1960, Ser. No. 31,186 3 Claims. (Cl. 125-37) This invention relates to grinding wheel dressers and more particularly to such dressers for truing portable grinding wheels, stones and the like.

The dressers of this invention are arranged for mounting on a bench or work table and are particularly adapted for the dressing of hand-held or portable grinding wheels and small stones. One embodiment includes a pair of dressing units mounted in spaced relation on a common base for the truing of the working surface of larger diameter portable grinding wheels by cradling the Wheel between the dressing suits. This arrangement substantially eliminates the vibration and chatter of such larger wheels in contact with the dresser and provides a working surface free of irregularities.

A further embodiment consists of a single bench mounted unit particularly adapted for truing the working surfaces of relatively small diameter, and often high speed, hand-held stones and Wheels. Such wheels which are dressed by this invention may take the for-m of mounted conical points used for reaming holes and which are usually discarded when they wear out of shape. The dresser of this invention provides for the restoration of the shape of such small stones thus extending the usefulness of the tool and reducing waste.

The dressers of this invention are of sturdy and long lasting construction combining ruggedness with ease of maintenance and replacement of the wearing components. The cutting disks are rotatably mounted on a sleeve bushing between a pair of integral upstanding support arms formed on a base. A spindle bolt extends through both the arms to support the sleeve, and a pair of hardened bushings are positioned at each of the arms to decrease wear.

It is therefore an object of this invention to provide a bench mounted dresser as outlined above for dressing grinding wheels of portable grinders.

A further object of this invention is to provide a bench mounted dresser as outlined above particularly suited for truing and restoring the working surface or contour of relatively small mounted stones and points.

Another object of this invention is to provide a bench mounted dresser as outlined above utilizing a pair of dressing units for reforming the working surface of larger portable grinding wheels without chatter or vibration.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawing, and the appended claims.

In the drawing FIG. 1 is a perspective view of the bench mounted dresser of this invention for truing larger portable grinding wheels;

FIG. 2 is a partially broken away elevation of one of the dressing units of the dresser of FIG. 1;

FIG. 3 is a perspective view of a modified form of the invention particularly suited for the dressing of small hand-held grinding wheels and stones;

FIG. 4 is a side view of a worn conical point before being dressed on the dresser of FIG. 3; and

FIG. 5 is an elevational view of the dresser of FIG. 3 showing the arrangement of the thin gauge cutter wheels and the manner of application of the stone of FIG. 4 thereto for dressing.

Referring to the drawing, which illustrates preferred 3,039,451 Patented June 19, 1962 embodiments of the invention, a bench mounted dresser is indicated at 10 in FIG. 1 as having a gray iron cast base 11 arranged for fixture to the surface 12 of a bench or work table. The base 11 is provided with notches 13 at each end thereof for receiving mounting bolts 14 by means of which the dresser 10 may be firmly secured to the table.

A pair of spaced apart dresser units 15 are mounted on the base 11 for engaging a grinding wheel 16 in peripherally spaced relation with the wheel 16 cradled between the units 15. Each of the dresser units 15 is formed with a central raised base portion -18 and a pair of spaced apart upstanding arms 19 and 20 integrally formed with the base 11. Each of the arms is drilled to form transverse axially aligned bores 21 therein.

Wear resisting bushings 25 are formed of hardened steel with a flange 26 formed at one end thereof and an integral cylindrical shank 27 of reduced diameter extending to one side of the flange 26. Each of the bushings 25 is also formed with a coaxial opening 28 there- The bushings 25 are mounted in each of the arms 19 and 20 with their shanks 27 press-fitted into the bores 21 of the arms, and with the flanges 26 flush against the inside surfaces of the arms. The bushings 25 support a spindle bolt 30 which is extended through the openings 28 in both of the bushings 25 and includes a head 31 received within a slot 32 formed in the outer surface of the arm 26) to hold the bolt 30 from turning. The bolt 30 therefore extends from the arm 20 through the opposite arm 19 and has an outer end threaded to receive a nut 32 adjacent the outside surface of the opposite arm 19. i

A hardened tubular sleeve 35 is rotatably mounted on the spindle bolt 30 between the flanges 26 of the bushings 25, and a plurality of cutter wheels 36 and separator disks 37 are rotatably mounted on the sleeve 35. In operation, the wheels 36 and disks 37 are free to rotate on the sleeve 35 and the sleeve, in turn, is free to rotate on the spindle bolt 30 providing a large bearing surface and a long trouble free service life.

In using the dresser of FIG. 1, the portable grinding wheel 16 is cradled between the units 15 and rotated with power. It has been found that the employment of two of the dresser units in a single bench mounted dresser substantially eliminates chatter and vibration of the wheel 16 when being trued and provides a superior surface quality to the wheel.

In the embodiment shown in FIG. 3, a bench mounted dresser 50 includes a cast gray iron base 51 supporting a single dresser unit 52 particularly suited for truing the surfaces of small Wheels and mounted stones, such as the cylindrical stone 53 carried within the chuck 54 of a hand tool, not shown, and the conical stone 55 of FIG. 4. The dresser 50 forms a substantially vibration free tool against which such smaller, and often high speed, stones may be trued, and is preferably constructed with the end bushings, a spindle bolt, and a sleeve bushing of the unit of FIG. 2.

An additional improvement consists of the employment of relatively thin gauge star-shaped cutter wheels 56, preferably having a thickness in the order of SO thousandths or less, as shown in FIG. 5, in lieu of the wheels 36 and separator disks 37 of FIG. 2. The wheels 56 are preferably employed contiguously side-by-side without separating disks to provide a fine cutting surface for use with the finer grade grinders, such as shown in FIG. 4.

In operation, the wheel or stone to be dressed is held in coaction with the cutter wheels of the bench mounted dresser at the desired angle and rotated while visually observing the results. The desired surface contour can therefore be readily obtained as both hands may be used to guide the wheel or stone into contact with the dresser, the dresser being securely mounted to a suitable work bench or table. The wheels 56 of the single unit dresser 50 and the wheels and disks 36 and 37 of the dresser 10 are readily replaceable when worn by the withdrawal of the spindle bolt 30. The sleeve 35 upon which the wheels are mounted is then free to be lifted from the base for replacement'with new cutter wheels, as desired.

It is therefore seen that this invention provides versatile dressers which eliminate waste by restoring to shape both the large and the small portable grinding wheels.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. A bench mounted grinding wheel dresser, comprising a base adapted for fixture to the surface of a shop bench and having a pair of spaced apart upstanding integral supporting arms, means in each of said arms defining transverse axially aligned bores, one of said arms being externally slotted adjacent the said bore therethrough and proportioned to receive a bolt head therein, a pair of bushings formed of hardened steel with a flange formed at one end thereof and an integral cylindrical shank of reduced diameter extending on one side of said flange, means in said bushings defining a smooth wall cylindrical opening coaxially therethrough, one each of said bushings being mounted with said shank within each of said bores and said flanges flush against the inside surfaces of said arms, a spindle bolt extending through the 2. A bench mounted grinding wheel dresser for truing small high speed stones, comprising a base adapted for fixture to the surface of a shop bench and having a pair of spaced apart upstanding integral supporting arms, means in each of said arms defining transverse axially aligned bores, a pair of bushings formed of hardened steel with a flange formed at one end thereof and an integral cylindrical shank of'reduced diameter extending on one side of said flange, means in said bushings defining an opening coaxially thereof, one each of said bushings being mounted with said shank within each of said bores and said flanges flush against the, inside surfaces of said arms, a spindle bolt extending through the openings in both said bushings with a head adjacent the outside surface of one of said arms and being threaded to receive a nut adjacent the outside surface of the other of said arms, a tubular sleeve rotatably mounted on said spindle bolt between the said flanges of said bushings, and a plurality of separate relatively thin gauge cutter wheels rotatably mounted in contiguous and free turning relation one to the other concentrically on said sleeve between said bushings for the truing of such stones brought into co- References Cited in the file of this patent UNITED STATES PATENTS 538,071 Hall Apr. 23, 1895 602,106 Roberts Apr. 12, 1898 1,552,005 Ogle Sept. 1, 1925 1,805,514 De Mattia May 19, 1931 2,469,871 Eaton May 10, 1949 FOREIGN PATENTS 813,870 Great Britain May 27, 1959 

